Safety switch



J. D. JORDAN SAFETY SWITCH July 11, 1950 Filed May 1, 1943 INVENTOR JAME$ D. JAN

Patented July 11, 1950 UNITED ST smear;

SAFETY SWITCH Application May 1, 1943, Serial No. 485,409

2 Claims.

This invention relates generally to electrical switches, and particularly to an electrical safety switch for use in rotating explosive projectiles.

An object of the invention is to provide a switch that may be mounted within a rotating projectile and positioned within an electrical detonating circuit to maintain said circuit inopen position until the projectile has been fired, after which the switch will be automatically actuated to close the circuit.

Another object of the invention is to provide a switch that will be locked in open position until the projectile hasbeen fired.

Another object of the inventionis toprovide a switch that will remain in open position during the period of setback created by. the firing of the projectile, so that the projectile will be unarmed until the same has left the, bore of the gun.

Another object of the invention is to provide a switch that will close when the projectile leaves the gun and thereafter will remain in closed position.

Another object of the invention is to provide a switch that is extremely simple in construction 1 and positive in operation.

Other objects of the invention, not specifically mentioned above, will become evident during the course of the following description.

In the drawings:

Figure 1 is a perspective view of a switch embodying the invention showing the parts in position to be assembled;

Figure 2 is a transverse sectional view taken on plane 2-2 of Figure 3, showing the switch in open position;

Figure 3 is a side elevational view of the invention;

Figure 4 is an enlarged framentary sectional view of a portion of the invention; and,

Figure 5 is an enlarged fragmentary sectional view of a portion of the invention showing the switch in closed position.

In the drawing, similar numerals of reference indicate like parts throughout the views.

The numeral Ill indicates the body member which is preferably in the form of a short, disclike cylinder, the body member being designed to be inserted within a rotatable explosive rojectile to rotate therewith. Preferably, the body member is positioned within the projectile so that the periphery thereof is in a surface parallel to the peripheral surface of the rotating projectile. A cylindrical bore l l is formed within the body member l0, and extends radially thereof from the outer periphery of the body member inwardly, terminating short of the central axis of the body member. The outer end of the bore H is provided with an enlarged recessed portion l2, and suitable screw threads l3 are machined in the outer end thereof. A shoulder M is formed between the enlarged'recessed portion l2 and the bore H. A circular insulating disc 55, having an aperture 16 centrally located therein, is positioned in the enlarged recessed portion !2- and abuts the shoulder M. A second insulating disc ll having a centrally located aperture 18 and diametrically opposed slots I9 therein is also inserted in the enlarged recessed portion l2 and is designed to abut the outer face of disc l5. It will be noted that the diameters of the apertures l6 and I8 are the same as the diameter of the bore ll. Mounted within the two opposed slots l9 are suitable binding plungers 19 which b-ind'contact members 20 between the discs l5 and 11. Contact members 20 are substantially U-shaped, and are formed of spring metal so that the contact portions thereof are slightly bowed and extend into the bore II. It should also be noted that the space between contact members 20 is slightly less than the diameter of the bore H. An imperforate insulating disc 2| is also positioned within the enlarged portion l2 of bore ll and bears against the outer sides of contacts 28 and disc H. A suitable set screw 22 is screwed into the threaded portion of the enlarged recess l2 and retains the discs l5, H, and 2!, together with the contact members 20, in their assembled position.

A movable electrically conductive contact member- 25, preferably a ball, is positioned within the bore II and will slide or roll from its innermost position outwardly upon the rotation of the body member Ill, and contact the contact members 20, as will be seen in Fig. 5. It should be noted at this point that when the contact ball 25 reaches its outermost position it forces the bowed portions of contact members 2!! apart and is held therebetween by frictional engagement therewith.

A bore 26 is also provided within the body member I I) and extends from the outer periphery thereof inwardly and intersects the bore ll. Screw threads 21 are provided within bore 28 at the outer end thereof. A plunger 28 is movably positioned within the bore 26, and is provided with a reduced guide stem 29. A screw cap 30 is positioned within the bore 26, and has a guide recess 3| into which the reduced guide stem 29 on the plunger 28 is designed to move.

A coil spring 32 is also mounted within the bore 26 and bears against the end of the screw cap 30 and the plunger 28 to tend to hold a portion of the plunger 28 within the bore II, as will readily be seen in Fig. 2.

The operation of the device will be readily understood from the foregoing description. As previously explained, the device is mounted in an explosive type rotating projectile and at least a portion of an electrical detonating circuit (not shown) is connected in series with contact members 20. As contact members 20 are spaced from each other, the electrical detonating circuit will be open. The device is mounted within the projectile so that the outer periphery thereof is in a plane transverse'to the axis of rotation of the" rotating projectile. Upon the firing of the projectile from a rifled gun bore, the force of the setback together with the compressive force of spring 32 will maintain the plunger 28 within the bore l I as shown in Fig. 2, thus maintaining the contact ball 25 in its innermost position. After the force of setback has been dissipated, the centrifugal force of the rotating projectile will throw the plunger 28 outwardly against the action of coil spring 32, and the plunger 28 will take the position shown in Fig. 5. After the plunger 28 has moved from the path of contact ball 25, the contact ball will also be thrown outwardly by centrifugal force and assume the position shown in Fig. 5. When this action has taken place, the projectile will have traveled from the bore of the gun. After the contact ball has entered the restricted opening between the spring metal contact members 20, the contact ball will be maintained in such position by the frictional engagement with the contact members. Thus, at least a portion of an electrical detonating circuit will be closed, thereby arming at least a portion of an explosive train within the projectile.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In combination with a rotatable explosive projectile, a safety switch for closing at least a portion of an electrical detonating circuit after the projectile has been fired from a gun, said switch comprising a disc shaped body member, a cylinder extending radially in said body member from the outer periphery inwardly, said cylinder being enlarged at its outer end, electrical contact members secured in said body member in spaced relation to each other and positioned respectively on opposite sides of said cylinder within the enlarged portion thereof, contact means slidable within. said cylinder by centrifugal force for bridging said contact members, and means for preventing said contact means from bridging said contact members until after the projectile has been fired from the gun, said last mentioned means including a bore in said body member and a plunger slidable in said bore by centrifugal force, said bore being positioned within said body member in substantially the same transverse plane of the projectile with and at right angles to said cylinder.

2. In combination with a rotatable explosive projectile, a safety switch for closing at least a portion of an electrical detonating circuit after the projectile has been fired from a gun, said switch comprising a disc shaped body member, a cylinder extending radially in said body member from the outer periphery inwardly, said cyl inder being enlarged at its outer end, a pair of diametrically opposed electrical contact members secured in said 'body member in spaced relation to each other and positioned in said'enlarged end of said cylinder, the distance between said contact members being less than the diameter of said cylinder, contact means movable within said cylinder by centrifugal force for bridging said contact members, said contact means being frictionally held in engagement with said contact members, and means for preventing said contact means from bridging said contact members until after the projectile has been fired, said last mentioned means including a bore in said body member and a spring pressed plunger slidable in said bore against the force of the spring by centrifugal force, said bore being positioned Within the body member in substantially the same transverse plane of the projectile with and at right angles to said cylinder.

JAMES D. JORDAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Italy 1939 

